U.S. patent number 10,333,296 [Application Number 15/959,143] was granted by the patent office on 2019-06-25 for surgical robotic arm with wireless power supply interface.
This patent grant is currently assigned to Verb Surgical Inc.. The grantee listed for this patent is Verb Surgical Inc.. Invention is credited to Jonathan Bernard, Koray Sahin, Qiong Wu.
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United States Patent |
10,333,296 |
Wu , et al. |
June 25, 2019 |
Surgical robotic arm with wireless power supply interface
Abstract
A proximal end portion of a robotic surgical arm is to be
coupled to an adapter of a surgical robotic platform, for use
during a surgical session at the platform, and then decoupled from
the adapter for storage until being re-coupled for use during
another surgical session at the platform. A resonant-mode
transformer-coupled power converter is provided that has a
secondary side and a primary side. The secondary side is in the arm
and has a transformer secondary coil in the proximal end portion of
the arm. The primary side has a transformer primary coil in the
adapter. The primary and secondary coils are held at positions and
orientations that enable mutual inductive coupling between them for
operation of the power converter when the arm is coupled to the
adapter. Other embodiments are also described and claimed.
Inventors: |
Wu; Qiong (San Jose, CA),
Sahin; Koray (Mountain View, CA), Bernard; Jonathan
(Santa Clara, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Verb Surgical Inc. |
Mountain View |
CA |
US |
|
|
Assignee: |
Verb Surgical Inc. (Mountain
View, CA)
|
Family
ID: |
66996779 |
Appl.
No.: |
15/959,143 |
Filed: |
April 20, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J
50/90 (20160201); H02J 1/00 (20130101); A61B
34/30 (20160201); H01F 38/14 (20130101); H02J
50/12 (20160201); A61B 2017/00477 (20130101); A61B
2018/00178 (20130101); A61B 2017/00221 (20130101) |
Current International
Class: |
A61B
34/30 (20160101); H02J 1/00 (20060101); H02J
50/90 (20160101); H02J 50/12 (20160101); A61B
17/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
US. Patent Application for related U.S. Appl. No. 15/785,921, filed
Oct. 17, 2017; 22 Pages. cited by applicant .
U.S. Patent Application for related U.S. Appl. No. 15/725,093,
filed Oct. 4, 2017 17 Pages. cited by applicant .
U.S. Patent Application for related U.S. Appl. No. 15/785,331,
filed Oct. 16, 2017 33 pages. cited by applicant .
Resonant LLC Converter: Operation and Design 250W 33Vin 400Vout
Design Example, Sam Abdel-Rahman; Infineon Technologies North
America Group (IFNA) Corp.; 2012; 19 Pages. cited by applicant
.
PCT Search Report and Written Opinion dated Nov. 27, 2018, for
related PCT Appln. No. PCT/US2018/030867 17 Pages. cited by
applicant.
|
Primary Examiner: Cavallari; Daniel J
Attorney, Agent or Firm: Womble Bond Dickinson (US) LLP
Claims
What is claimed is:
1. A surgical robotic apparatus comprising: a surgical robotic arm
having a proximal end portion and a distal end portion, where the
distal end portion is configured to receive a surgical tool, and
the proximal end portion is configured to be removably coupled to
an adapter of a surgical robotic platform for surgery and decoupled
from the adapter for storage; and a secondary side of a
resonant-mode transformer-coupled power converter that also has a
primary side, wherein the secondary side of the power converter has
a transformer secondary coil in the proximal end portion of the
arm, and wherein the primary side has a transformer primary coil in
the adapter, and wherein the primary and secondary coils are held
at positions and orientations that enable mutual inductive coupling
between them for operation of the power converter when the arm is
coupled to the adapter.
2. The apparatus of claim 1 wherein the proximal end of the arm
comprises a coupling member formed as a receptacle to receive and
hold the adapter, wherein the coupling member has a mechanical
latching mechanism that latches the coupling member to the adapter,
in a detachable and re-attachable manner.
3. The apparatus of claim 1 wherein the proximal end of the arm
comprises: a male coupling member that is to be received by and
held by the adapter, wherein the male coupling member has a
mechanical latching mechanism that latches the male coupling member
to the adapter, in a detachable and re-attachable manner.
4. The apparatus of claim 1 wherein the secondary coil and the
primary coil are fixed in position relative to each other once the
arm has been coupled to the adapter.
5. The apparatus of claim 4 wherein the secondary coil is part of a
second part of a multi-part transformer that also has a first part,
wherein the multi-part transformer is of a core form or a shell
form in which each of the primary coil and the secondary coil is
wound around a respective, magnetic or ferromagnetic core or shell
portion, and wherein the second part of the multi-part transformer
is in the proximal end of the arm while the first part is in the
adapter.
6. The apparatus of claim 5 wherein the first part of the
multi-part transformer has a flat face that becomes aligned with,
and is held at a fixed distance from, the second part of the
multi-part transformer when the arm has been coupled to the
adapter, and wherein in that position there is an electrically
insulating gap between the primary coil and the secondary coil.
7. The apparatus of claim 1 wherein the primary and secondary coils
are parts of a multi-part transformer, wherein the multi-part
transformer is of a core form or a shell form in which each of the
primary coil and the secondary coil is wound around a respective,
magnetic or ferromagnetic core or shell portion, and wherein the
part of the multi-part transformer that has the secondary coil is
in the proximal end of the arm while the part that has the primary
coil is in the adapter.
8. The apparatus of claim 7 wherein the multi-part transformer
comprises a first support plate that supports the primary coil, and
a second support plate that supports the secondary coil, and
wherein the first and second supports are parallel to each other
and separated when the arm has been coupled to the adapter.
9. The apparatus of claim 1 wherein the secondary coil is part of a
second part of a multi-part magnetic transformer that also has a
first part, wherein the multi-part magnetic transformer is of a
coreless form, and wherein the second part of the multi-part
transformer is in the proximal end of the arm while the first part
is in the adapter.
10. The apparatus of claim 1 further comprising an electrical load
coupled to an output of the power converter, wherein the electrical
load comprises: a communications interface in the arm, configured
to receive an arm actuator control signal; and motor driver
circuitry in the arm that is coupled to the communications
interface and configured to be controlled by the arm actuator
control signal.
11. The apparatus of claim 9 wherein the power converter comprises
an optical coupler having a transmitter that is affixed to the
proximal end of the arm and transmits a feedback signal derived
from the output of the power converter, and wherein the optical
coupler has a receiver that is affixed to the adapter and receives
the feedback signal when the arm is coupled to the adapter.
12. The apparatus of claim 10 further comprising the adapter,
wherein the adapter of the surgical robot platform is a table
adapter that is configured to be attached to a surgical table.
13. The apparatus of claim 12 wherein the adapter comprises a pivot
joint that enables the coupling member to rotate about a pivot axis
of the joint.
14. The apparatus of claim 1 wherein the power converter comprises
an optical coupler having a transmitter that is affixed to the
proximal end of the arm and transmits a feedback signal derived
from the output of the power converter, and wherein the optical
coupler has a receiver that is affixed to the adapter and receives
the feedback signal when the arm is coupled to the adapter.
15. A surgical robotic apparatus comprising: a surgical robotic arm
having a proximal end portion and a distal end portion, where the
distal end portion is configured to receive a surgical robotic
tool, and the proximal end portion is configured to be removably
coupled to a surgical robotic platform for surgery and decoupled
from the platform for storage; and a secondary side of a
resonant-mode transformer-coupled power converter that also has a
primary side, wherein the secondary side of the power converter has
a transformer secondary coil in the proximal end portion of the
arm, and wherein the primary side has a transformer primary coil in
the platform, and wherein the primary and secondary coils are held
at positions and orientations that enable mutual inductive coupling
between them for operation of the power converter when the arm is
coupled to the platform for wireless power transfer through the
transformer primary and secondary coils.
16. The apparatus of claim 15 wherein the secondary coil and the
primary coil are fixed in position relative to each other once the
arm has been coupled to the platform.
17. The apparatus of claim 16 wherein the secondary coil is part of
a second part of a multi-part transformer that also has a first
part, wherein the multi-part transformer is of a core form or a
shell form in which each of the primary coil and the secondary coil
is wound around a respective, magnetic or ferromagnetic core or
shell portion, and wherein the second part of the multi-part
transformer is in the proximal end of the arm while the first part
is in the platform.
18. The apparatus of claim 17 wherein the first part of the
multi-part transformer has a flat face that becomes aligned with,
and is held at a fixed distance from, the second part of the
multi-part transformer when the arm has been coupled to the
platform, and wherein in that position there is an electrically
insulating gap between the primary coil and the secondary coil.
19. The apparatus of claim 18 wherein the multi-part transformer
comprises a first support plate that supports the primary coil, and
a second support plate that supports the secondary coil, and
wherein the first and second supports are parallel to each other
and separated when the arm has been coupled to the table.
20. The apparatus of claim 15 wherein the proximal end of the arm
comprises a coupling member formed as a receptacle to receive and
hold part of the platform, wherein the coupling member has a
mechanical latching mechanism that latches the coupling member to
said part of the platform, in a detachable and re-attachable
manner.
Description
FIELD
An embodiment of the invention relates to power supplies for
surgical robotic arms. Other embodiments are also described.
BACKGROUND
In a surgical robotic system, a robotic arm that has a surgical
tool attached to it its distal end is remotely operated by a
surgeon. Applications include endoscopic surgery, which involves
looking into a patient's body and performing surgery inside, for
example the abdominal cavity, using endoscopes and other surgical
tools that are attached to the ends of several robotic arms. The
system gives the surgeon a close-up view of the surgery site, and
also lets the surgeon operate the tool that is attached to the arm,
all in real-time. The tool may be a gripper with jaws, a cutter, a
video camera, or an energy emitter such as a laser used for
coagulation. The tool is thus controlled in a precise manner with
high dexterity in accordance with the surgeon manipulating a
handheld controller.
In a typical surgical robotic session, there may be up to five arms
that need to be ready for being deployed at a surgical robotic
platform, such as a table or bed on which the patient is resting.
Installed within each arm is a communications interface for
receiving robotic commands from, and providing for example video
data to, a computerized, surgical console at which the surgeon sits
while viewing a display screen that shows the surgical site and
while manipulating the hand controller. Also installed within each
arm is arm joint driver and control circuitry, and tool driver and
control circuitry; the arm joint driver and control circuitry can
drive several motorized joints (actuators) to pivot or translate
various links of the arm so that the distal end of the arm is moved
to a desired position as dictated by a user command; the tool
driver and control circuitry can drive for example a gripper or
cutter actuator or an energy emitter in the surgical tool (as
dictated by a user command.) Electrical power that supplies the
communications interface and the arm joint and tool driver and
control circuitry may be delivered to the arm, via a power cable
that is separate from the arm but connected to the arm at one end
and to the surgical robotic platform at another end (e.g., to a
power supply at the surgical table.) Alternatively, power may
delivered to the arm through the use of pogo pins that come into
electrical contact at a physical interface between the arm and an
arm adapter at the robotic platform, when the arm is attached to
the arm adapter.
SUMMARY
An embodiment of the invention is a surgical robotic arm having a
wireless power supply interface to a surgical robotic platform. The
arm has a proximal end portion and a distal end portion. The distal
end portion is configured to receive a surgical tool. The proximal
end portion is coupled to the surgical robotic platform, for
example to an adapter of a surgical table on which a patient lies.
The adapter adapts the surgical table to be coupled to the arm, so
that the arm can be used for performing a surgery on the patient
(while the patient is lying on the surgical table.) In one
embodiment, the functions of the adapter may be viewed as being
provided by the platform. The arm may have several linkages and
actuated (motorized) joints in between adjacent linkages. The
linkages can thus be rotated about a pivot axis at each joint, or
can otherwise moved, when power is supplied to arm joint driver
circuitry that drives the actuators. The proximal end portion of
the arm is also configured for being decoupled from the adapter,
for storage of the arm until it is to be re-coupled for use during
another surgical session at the platform.
To achieve wireless or contactless electrical power transfer
between the surgical robotic platform and an electrical load in the
arm, a resonant-mode transformer-coupled power converter is
provided. The power converter has a primary side and a secondary
side, where the primary side has a transformer primary coil that is
in the adapter (of the platform), while the secondary side has a
transformer secondary coil that is in the proximal end portion of
the arm. Once the arm is coupled to the adapter, the primary and
secondary coils are held at relative positions and orientations
that enable mutual inductive coupling between them, for proper
operation of the power converter which delivers the full power
needed by the electrical load during the surgery. This avoids the
need for pogo pins or separate power cables and power connectors,
to deliver sufficient and reliable electrical power from the
platform to the electrical load that is in the arm. This solution
is especially desirable since the arm has to not only be coupled to
the adapter, but then decoupled for storage once the surgery is
over, and then recoupled to the adapter for another surgery, where
this cycle repeats quite often (e.g., more than a handful of
surgical sessions in a single day): the wireless power supply
interface may be more reliable in the long term than electrical
contact-based connectors or pogo pins which can degrade over time
particularly at high current levels and are difficult to keep
clean. Also, the no-contact wireless power supply interface may be
washable in the operating room, another important convenience. The
solution is also especially advantageous as there are several such
arms that are coupled to the robotic platform and are needed for
simultaneous operation during the surgery.
In one embodiment, the adapter at the robotic platform and the
proximal end portion of the arm are configured so that the primary
and secondary coils are fixed in position relative to each other
once the arm has been coupled to the adapter, and remain in the
same relative position while the arm is then used during a
surgery.
In one embodiment, the adapter may have a pivot joint. A mechanical
latching mechanism is provided that latches the arm to the pivot
joint in the adapter, in a detachable and re-attachable manner. The
pivot joint in the adapter enables the arm to rotate about a pivot
axis of the joint. In that case, the secondary coil and the primary
coil remain fixed in position relative to each other but move as
one with the arm as the arm rotates around the pivot joint of the
adapter.
As mentioned above, an electrical load in the arm is coupled to the
output of the secondary side of the power converter. The load may
include a communications interface and motor and energy emitter
driver circuitry, where the latter drives several actuators (at
multiple joints including one or more at the surgical tool) and, if
attached, an energy emitting surgical tool. The driving is in
accordance with several arm linkage joint control signals and one
or more tool control signals, that are received by the
communications interface, for example from a control tower. The
control tower may have translated user commands received from a
surgical console (signals that are sensing the orientation or
position of a handheld controller), and based on robotic feedback
information from the arm (e.g., accelerometer output data, thermal
sensor output data, etc.) into robotic commands (arm linkage joint
control signals in the arm's joint space, and one or more tool
control signals) for the arm.
In one embodiment, the actuator control signals as well as any
other control signals that are not part of the wireless electrical
power delivery interface to the arm (which may be a resonant mode
transformer coupled power converter as described above) are
received and transmitted by the communications interface through a
communications cable that may run from the arm to the control tower
3. Such a communications cable is thus in addition to the wireless
power delivery interface, at each arm. The communications interface
may also give robotic status feedback to generate the next command,
and other status such as power consumption, temperature from a
sensor in the arm or in the tool, and position from an
accelerometer in the arm or in the tool.
The above summary does not include an exhaustive list of all
aspects of the present invention. It is contemplated that the
invention includes all systems and methods that can be practiced
from all suitable combinations of the various aspects summarized
above, as well as those disclosed in the Detailed Description below
and particularly pointed out in the claims filed with the
application. Such combinations have particular advantages not
specifically recited in the above summary.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the invention are illustrated by way of example
and not by way of limitation in the figures of the accompanying
drawings in which like references indicate similar elements. It
should be noted that references to "an" or "one" embodiment of the
invention in this disclosure are not necessarily to the same
embodiment, and they mean at least one. Also, in the interest of
conciseness and reducing the total number of figures, a given
figure may be used to illustrate the features of more than one
embodiment of the invention, and not all elements in the figure may
be required for a given embodiment.
FIG. 1 is a pictorial view of an example surgical robotic system in
an operating arena.
FIG. 2A shows an embodiment of a robotic surgical arm that is
uncoupled from an example surgical robotic platform.
FIG. 2B shows the arm in its coupled state.
FIG. 2C shows the arm in its coupled state and ready to be used in
the surgical operation.
FIG. 3 is a circuit schematic of an example resonant mode
transformer coupled power converter that enables wireless power
transfer to the robotic surgical arm.
FIG. 4A is a perspective view of two parts of a multi-part
transformer that may be used in the power converter.
FIG. 4B is a perspective view of the multi-part transformer in the
coupled state, where the constituent parts have been brought
adjacent to each other to enable mutual inductance coupling between
the primary and secondary coils.
DETAILED DESCRIPTION
Several embodiments of the invention with reference to the appended
drawings are now explained. Whenever the shapes, relative positions
and other aspects of the parts described in the embodiments are not
explicitly defined, the scope of the invention is not limited only
to the parts shown, which are meant merely for the purpose of
illustration. Also, while numerous details are set forth, it is
understood that some embodiments of the invention may be practiced
without these details. In other instances, well-known circuits,
structures, and techniques have not been shown in detail so as not
to obscure the understanding of this description.
Referring to FIG. 1, this is a pictorial view of an example
surgical robotic system 1 in an operating arena. The robotic system
1 includes a user console 2, a control tower 3, and one or more
surgical robotic arms 4 at a surgical robotic platform 5, e.g., a
table, a bed, etc. The system 1 can incorporate any number of
devices, tools, or accessories used to perform surgery on a patient
6. For example, the system 1 may include one or more surgical tools
7 used to perform surgery. A surgical tool 7 may be an end effector
that is attached to a distal end of a surgical arm 4, for executing
a surgical procedure.
Each surgical tool 7 may be manipulated manually, robotically, or
both, during the surgery. For example, the surgical tool 7 may be a
tool used to enter, view, or manipulate an internal anatomy of the
patient 6. In an embodiment, the surgical tool 7 is a grasper that
can grasp tissue of the patient. The surgical tool 7 may be
controlled manually, by a bedside operator 8; or it may be
controlled robotically, via actuated movement of the surgical
robotic arm 4 to which it is attached. The robotic arms 4 are shown
as a table-mounted system, but in other configurations the arms 4
may be mounted in a cart, ceiling or sidewall, or in another
suitable structural support.
Generally, a remote operator 9, such as a surgeon or other
operator, may use the user console 2 to remotely manipulate the
arms 4 and/or the attached surgical tools 7, e.g., teleoperation.
The user console 2 may be located in the same operating room as the
rest of the system 1, as shown in FIG. 1. In other environments
however, the user console 2 may be located in an adjacent or nearby
room, or it may be at a remote location, e.g., in a different
building, city, or country. The user console 2 may comprise a seat
10, foot-operated controls 13, one or more handheld user input
devices, UID 14, and at least one user display 15 that is
configured to display, for example, a view of the surgical site
inside the patient 6. In the example user console 2, the remote
operator 9 is sitting in the seat 10 and viewing the user display
15 while manipulating a foot-operated control 13 and a handheld UID
14 in order to remotely control the arms 4 and the surgical tools 7
(that are mounted on the distal ends of the arms 4.)
In some variations, the bedside operator 8 may also operate the
system 1 in an "over the bed" mode, in which the beside operator 8
(user) is now at a side of the patient 6 and is simultaneously
manipulating a robotically-driven tool (end effector as attached to
the arm 4), e.g., with a handheld UID 14 held in one hand, and a
manual laparoscopic tool. For example, the bedside operator's left
hand may be manipulating the handheld UID to control a robotic
component, while the bedside operator's right hand may be
manipulating a manual laparoscopic tool. Thus, in these variations,
the bedside operator 8 may perform both robotic-assisted minimally
invasive surgery and manual laparoscopic surgery on the patient
6.
During an example procedure (surgery), the patient 6 is prepped and
draped in a sterile fashion to achieve anesthesia. Initial access
to the surgical site may be performed manually while the arms of
the robotic system 1 are in a stowed configuration or withdrawn
configuration (to facilitate access to the surgical site.) Once
access is completed, initial positioning or preparation of the
robotic system 1 including its arms 4 may be performed. Next, the
surgery proceeds with the remote operator 9 at the user console 2
utilizing the foot-operated controls 13 and the UIDs 14 to
manipulate the various end effectors and perhaps an imaging system,
to perform the surgery. Manual assistance may also be provided at
the procedure bed or table, by sterile-gowned bedside personnel,
e.g., the bedside operator 8 who may perform tasks such as
retracting tissues, performing manual repositioning, and tool
exchange upon one or more of the robotic arms 4. Non-sterile
personnel may also be present to assist the remote operator 9 at
the user console 2. When the procedure or surgery is completed, the
system 1 and the user console 2 may be configured or set in a state
to facilitate post-operative procedures such as cleaning or
sterilization and healthcare record entry or printout via the user
console 2.
In one embodiment, the remote operator 9 holds and moves the UID 14
to provide an input command to move a robot arm actuator 17 in the
robotic system 1. The UID 14 may be communicatively coupled to the
rest of the robotic system 1, e.g., via a console computer system
16. The UID 14 can generate spatial state signals corresponding to
movement of the UID 14, e.g. position and orientation of the
handheld housing of the UID, and the spatial state signals may be
input signals to control a motion of the robot arm actuator 17. The
robotic system 1 may use control signals derived from the spatial
state signals, to control proportional motion of the actuator 17.
In one embodiment, a console processor of the console computer
system 16 receives the spatial state signals and generates the
corresponding control signals. Based on these control signals,
which control how the actuator 17 is energized to move a segment or
link of the arm 4, the movement of a corresponding surgical tool
that is attached to the arm may mimic the movement of the UID 14.
Similarly, interaction between the remote operator 9 and the UID 14
can generate for example a grip control signal that causes a jaw of
a grasper of the surgical tool 7 to close and grip the tissue of
patient 6.
The surgical robotic system 1 may include several UIDs 14, where
respective control signals are generated for each UID that control
the actuators and the surgical tool (end effector) of a respective
arm 4. For example, the remote operator 9 may move a first UID 14
to control the motion of an actuator 17 that is in a left robotic
arm, where the actuator responds by moving linkages, gears, etc.,
in that arm 4. Similarly, movement of a second UID 14 by the remote
operator 9 controls the motion of another actuator 17, which in
turn moves other linkages, gears, etc., of the robotic system 1.
The robotic system 1 may include a right arm 4 that is secured to
the bed or table to the right side of the patient, and a left arm 4
that is at the left side of the patient. An actuator 17 may include
one or more motors that are controlled so that they drive the
rotation of a joint of the arm 4, to for example change, relative
to the patient, an orientation of an endoscope or a grasper of the
surgical tool 7 that is attached to that arm. Motion of several
actuators 17 in the same arm 4 can be controlled by the spatial
state signals generated from a particular UID 14. The UIDs 14 can
also control motion of respective surgical tool graspers. For
example, each UID 14 can generate a respective grip signal to
control motion of an actuator, e.g., a linear actuator, that opens
or closes jaws of the grasper at a distal end of surgical tool 7 to
grip tissue within patient 6.
In some aspects, the communication between the platform 5 and the
user console 2 may be through a control tower 3, which may
translate user commands that are received from the user console 2
(and more particularly from the console computer system 16) into
robotic control commands that transmitted to the arms 4 on the
robotic platform 5. The control tower 3 may also transmit status
and feedback from the platform 5 back to the user console 2. The
communication connections between the robotic platform 5, the user
console 2, and the control tower 3 may be via wired and/or wireless
links, using any suitable ones of a variety of data communication
protocols. Any wired connections may be optionally built into the
floor and/or walls or ceiling of the operating room. The robotic
system 1 may provide video output to one or more displays,
including displays within the operating room as well as remote
displays that are accessible via the Internet or other networks.
The video output or feed may also be encrypted to ensure privacy
and all or portions of the video output may be saved to a server or
electronic healthcare record system.
A surgical robotic apparatus that has a wireless power supply
interface is now described. Referring to FIG. 2A, an example of a
robotic surgical arm 4 is shown that is supported by a wheeled cart
43 and is ready to be coupled to the surgical robotic platform 5
for use during surgery upon the patient 6. Here, a human patient is
shown as an example, lying flat on the upper face of a surgical
tabletop 34. In this example, the surgical robotic platform 5
includes a surgical table 32 composed of the tabletop 34 on which
the patient is lying on, and a table support 35 such as a pedestal
that has raised the tabletop 34 above a floor and is stabilized by
a table base 36 that is on the floor. The table support 35 may
allow the tabletop 34 to have adjustable height, pitch, yaw or roll
so as to enable a user such as a surgeon or assistant surgeon or
nurse to perform a surgical procedure upon the patient 6 at a
desired orientation or position. The table support 35 may also
enable the tabletop 34 to be adjustable horizontally, either in a
length direction of the tabletop or in a width direction.
The robotic arm 4 has a proximal end portion 39 and a distal end
portion 38, between which are two or more (in the example shown
here, three) arm joints 41. Each joint 41 is coupled to an adjacent
pair of linkages. In the example shown, the arm 4 has three
linkages but in general there may be more. The joints are motorized
to enable precise and dexterous positioning of the distal end
portion 38 to which a surgical tool 7 is attached, so that the
distal end of the tool 7 can be precisely positioned inside the
patient 6 during surgery. The linkage at the distal end portion 8
is configured to receive any one of several types of surgical tools
7 (not shown) such as any one of those mentioned earlier in
connection with FIG. 1.
The robotic surgical arm 4 also has its proximal end portion 39
that is configured, by virtue of its coupling member 40, to be
coupled to an adapter 37 of the surgical robotic platform 5, for
use during a particular surgery session at the platform 5. In the
example shown, the adapter 37 is secured to a surgical table 32. In
other surgical platforms 5 however, the adapter 37 may be attached
to for example a cart, a ceiling, a sidewall, or even another
suitable support structure.
There may be several adapters 37 coupled to (or part of) the
surgical robotic platform 5, where each is to receive a respective
arm 4, but in the interest of conciseness FIG. 2A shows only one
coupled to the surgical table 32. Each adapter 37 has a mechanical
latching mechanism that latches the coupling member 40 of the arm 4
to the adapter 37, in a secure but detachable and re-attachable
manner. The latching mechanism may be manually (human user)
actuated by a lever or other hand-operated feature, or it may be
motorized and automatically controlled to latch itself once the
coupling member 40 of the arm 4 has been placed into position in a
complementary part of the latching mechanism, as seen in FIG. 2B
for example. The adapter 37 may be a rigid structural support
member that mechanically engages with the coupling member 40 at the
proximal end portion 39 of the arm 4, so as to securely affix the
proximal end portion of the arm 4 to the robotic platform 5 in what
is referred to here as its coupled state (during the surgical
operation.) In the example shown, the adapter 37 is anchored to the
tabletop support 35, and extends laterally or horizontally outward
from the tabletop support 35. The adapter 37 may be affixed to the
tabletop support 35 so as to move as one with the former, as the
position and orientation of the tabletop 34 is adjusted.
Alternatively, the adapter 37 may be affixed directly to the bottom
or side of the tabletop 34, or directly to the floor through a
separate support member (that is separate from the tabletop support
35 and that may also be adjustable in position (height) or
orientation.)
In the robotic surgery arm 4, the coupling member 40 is designed so
that it can be de-coupled from the adapter 37 once the surgery
session has ended, so that the arm 4 can then be stored (e.g., on
the cart 43), until the arm 4 is to be re-coupled to the adapter 37
for use during another surgical session at the platform. To
illustrate this, FIG. 2A shows how the height of a support member
42 of the cart 43 has been adjusted so that a mouth of the coupling
member 40 is brought to the same height as the adapter 37. Next,
the cart 43 is wheeled towards the surgical table 32 until the
mouth of the coupling member 40 engages the outside end of the
adapter 37, and is then locked into that coupled position by the
latching mechanism--see FIG. 2B. The cart 43 is then wheeled away
from the surgical table 32 thereby leaving behind the coupled arm
4, as seen in FIG. 2C. The arm 4 is now ready for use in the
surgical operation. This procedure may be repeated to bring a total
of two, three or more arms into their coupled states at the
surgical table 32, where each arm is locked into a fixed position
at its respective adapter 37.
It should be noted that while the figures illustrate the example
where the coupling member 40 of the arm 4 is a receptacle that
receives and holds a "male" outside end of the adapter 37, an
alternative is that the outside end of the adapter 37 is configured
as a receptacle that receives and holds a male coupling member
40.
In another embodiment of the invention, the adapter 37 can pivot
around a pivot joint (not shown), such that once the arm 4 is in
its coupled state, it too will pivot about the pivot joint. The
mechanical latching mechanism in that case may latch the coupling
member 40 of the arm 4 to a complementary part of the adapter 37
that also pivots. The pivot axis may, for example, be a vertical
axis. The mechanical latching mechanism for this embodiment may
also be configured to detach and re-attach the arm 4, by for
example being manually (human user) actuated by a lever or other
hand-operated feature, or it may be motorized and automatically
controlled to latch itself once the proximal end of the arm has
been placed into position (at a complementary part of the latching
mechanism that is on the pivot joint.)
Still referring to FIGS. 2A-2C, these figures also illustrate how
wireless power transfer can be achieved, from the surgical robotic
platform 5 to the electrical load in the arm 4, using a resonant
mode transformer coupled power converter. The power converter may
have a primary side 47 at the surgical platform 5, e.g., attached
to the surgical table 32 as shown, that is coupled via mutual
inductance to a secondary side 48 that is in the arm 4. The primary
side 47 feeds power to a transformer primary part 44 that is in the
adapter 37, while a transformer secondary part 45 that is in the
arm 4 receives that power and feeds it to the secondary side 48.
Examples of the transformer primary and secondary parts are shown
in FIG. 4A and in FIG. 4B to be discussed below. More generally,
the transformer primary part 44 has a transformer primary coil or
multi-turn winding that may be housed in the adapter 37, and the
transformer secondary part 45 has a transformer secondary coil or
multi-turn winding that may be housed in the proximal end portion
39 of the arm, and more specifically in the coupling member 40. The
primary and secondary coils, or the primary part 44 and the
secondary part 45, may be rigidly held at fixed positions and
orientations relative to each other (once the arm 4 is coupled to
the adapter 37 as seen for example in FIG. 2B and in FIG. 2C) that
enable mutual inductive coupling between them for operation of the
power converter.
As mentioned above, the electrical load in the arm 4 is powered by
the output of the secondary side 48 of the power converter. The
load may include a communications interface (communications
circuitry), arm joint motor driver and control circuitry including
arm joint brake driver and control circuitry (e.g., including
brushless dc motor controllers), digital camera electronics, and
energy emitter driver circuitry. The communications interface may
be, for example, a serial peripheral interface bus, SPI, or other
reliable digital communications interface that can deliver the arm
linkage joint control and tool control signals from a computer
system at the surgical platform 5, e.g., the control tower 3. The
control tower 3 may have translated user commands received from the
surgical console 2 (signals that are sensing the orientation or
position of a handheld controller) and robotic feedback signals
from the arm, into robotic commands, which may be the arm linkage
joint control signals in the arm's joint space, and one or more
tool control signals for the arm.
The arm joint motor driver and control circuitry drives or
energizes several actuators (at multiple joints) in accordance with
several arm linkage joint control signals that are received from
the robotic surgical platform 5 (e.g., from the control tower
3--see FIG. 1), by the communications interface. The digital camera
electronics forms part of a digital camera in the surgical tool 7,
e.g., an endoscopic camera. The energy emitter driver circuitry
serves to energize one or more energy emitters that are in the
surgical tool 7, such as a coagulation laser or an ultrasonic
emitter. In one embodiment, the actuator control signals as well as
any other control signals that are not part of the wireless
electrical power delivery interface to the arm 4 (which may include
a resonant mode transformer coupled power converter as described
above) are received and transmitted by the communications interface
through a communications cable that may run from the arm 4 to the
robotic surgical platform 5, e.g., to the surgical table 32 and
then to the control tower 3.
FIG. 3 shows a circuit schematic of an example of the resonant mode
transformer coupled power converter. The primary side 47 of the
power converter has a group of solid state switches (depicted in
the example here as metal oxide semiconductor field effect
transistors) that route power from a dc voltage rail at Vin(dc).
The primary side 47 be housed in the adapter 37 as shown in FIG.
2A, but it could alternatively be housed in the tabletop support
35, in the base 36, or elsewhere on the surgical table 32 or even
in another element of the robotic surgical platform 5. The dc
voltage rail at Vin(dc) may be produced by a platform power supply
(not shown), such as an ac-dc power converter that converts 120
Vac/240 Vac "wall power" that may be available in the operating
room, to a suitable dc voltage. The platform power supply supplies
the power that is drawn by the resonant mode power converter, which
is in turn supplying the power that is drawn by the electrical load
in the coupled arm 4. In other words, the output Vout(dc) of the
resonant mode power converter is a power supply to the
communications interface circuitry and the arm joint and tool
driver circuitry in the arm 4, as described above. Just as an
example, Vout(dc) may be 48 Vdc at 200 Watts.
The switches in the primary side 47 route power from Vin(dc) to
feed a transformer primary coil Lp. The latter is part of a primary
side resonant circuit, which is formed together with a capacitor Cp
in the primary side 47. The switches are turned on and turned off
under control of a switch mode power supply resonant controller
also in the primary side 47, e.g., a transformer driver that drives
the primary side resonant circuit with a 50% duty cycle square wave
having a controlled working (switching) frequency, in order to
transfer power to the secondary side 48 in a controlled, efficient
manner, as needed by the electrical load in the arm 4 that is
coupled to the output of the secondary side 48 at Vout(dc). The
secondary side 48 has a transformer secondary coil Ls, which is
part of a secondary side resonant circuit along with capacitor Cs.
There is mutual inductive coupling of magnetic flux across a
non-conductive (electrically insulating) gap 46 between the coils,
from the transformer primary part 44 to the transformer secondary
part 45. This enables switch mode power transfer from the primary
side 47 to the secondary side 48. The power required by the load
may be met by changing the switching frequency of the control
signal of the resonant controller in the primary side 47, e.g., by
matching the switching frequency with the resonance frequency of
the L-C based resonant circuit in the primary side in order to
increase power transfer. The closer the switching frequency to the
resonant frequency (fr) of Lp and Cp, the higher the voltage at the
secondary side 48. When Vout is lower than the setting voltage,
which may be for example 48 V, the feedback signals make the
controller switching frequency closer to the resonant frequency
(fr) to make Vout higher. When Vout great than the setting voltage,
the feedback signal can force the switching frequency away from fr
to make Vout lower. The feedback signal is an analog signal, e.g.,
Vfb, and as explained below may be converted into a PWM waveform
before being passed over an optical interface over the gap, or
alternatively by the communication interface circuitry mentioned
above. Note that the turns ratio of the primary coil to the
secondary coil need not be 1:1.
The ac (switched) voltage at the output of the resonant circuit
Ls-Cs is converted into dc by a rectifier (in this example, a full
wave rectifier composed of the four diodes as shown) and then
filtered by a filter capacitor Cf, resulting in the output voltage
Vout(dc). If regulation of Vout(dc) is desired, then this may be
achieved by configuring the resonant controller to vary the
switching frequency of its control of the switches, in a feedback
controlled manner. This would be in response to a feedback voltage
Vfb that represents an error or difference between a reference
voltage Vref and the power converter output voltage Vout(dc). The
feedback voltage Vfb may be provided to the resonant controller,
not in its original form but rather in the form of Vfb', where Vfb
is converted in the secondary side 48 into a PWM signal, before it
is then transmitted by an optical transmitter 54 of an optical
coupler to an optical receiver 55 in the primary side 47, where it
is then converted back into analog form as Vfb' before being used
by the resonant controller. The technique of converting the
feedback signal into digital form (e.g., as a PWM signal) for its
transfer from the arm 4 to the robotic surgical platform 5
increases immunity to noise during the transfer. Other techniques
for delivering the feedback voltage Vfb from the secondary side 48
to the primary side 47 in a wireless or contactless manner across
the electrically insulating gap 46 include the use of an auxiliary
transformer. In yet another embodiment, the feedback voltage Vfb'
is received in the primary side 47 via a cabled communications
interface with the secondary side 48 in the arm 4, e.g., the same
SPI that is used by the communications interface in the arm 4 for
receiving the robotic commands from the control tower 3.
FIG. 4A and FIG. 4B are perspective views of the two parts of an
example multi-part transformer, that may be used in the resonant
mode transformer coupled power converter of FIG. 3. The transformer
primary part 44, which is in the proximal coupling member 40 of the
arm 4 (see FIGS. 2A-2C), and has a primary coil that terminates in
a pair of primary terminals 51. There is also the transformer
secondary part 45, which is in the adapter 37 and has a secondary
coil that terminates in a pair of secondary terminals 52. FIG. 4A
shows the transformer in its un-coupled state, when the arm 4 has
been de-coupled from the adapter 37 for purposes of storage--see
FIG. 2A: the primary part 44 is spaced so far apart from the
secondary part 45 that there is insufficient mutual inductive
coupling between them (to transfer enough power to supply the
electrical load in the arm 4.) In contrast, FIG. 4B shows the
transformer in its coupled state, when the arm 4 is coupled to the
adapter 37--see FIG. 2C. There, the primary part 44 has been
brought close enough to the secondary part 45 such that the two are
separated only by the gap 46--see FIG. 3. This state allows
sufficient power to be transferred from the primary to the
secondary (so as to supply the electrical load in the arm 4.)
In the particular example of FIG. 4A and FIG. 4B, the multi-part
transformer may have a core form or a shell form in which each of
the primary coil and the secondary coil is wound around a
respective, magnetic or ferromagnetic core or shell portion that
may be composed of laminated steel (steel sheets lying in the x-y
plane and stacked in the z-direction.) As seen in the figures, in
each of the primary part 44 and the secondary part 45 of the
transformer, there is a pair of support plates that support the
coil of that part, one on the left side and another on the right
side of the coil. The four support plates are all parallel to each
other, and the two inner ones may be separated by less than 5 mm
once the arm 4 has been coupled to the adapter 37 (resulting in the
coupled state shown in FIG. 4B.) For each of the primary part 44
and the secondary part 45 of the transformer, the core form or
shell form part may be composed of magnetic or ferromagnetic
material such as laminated steel.
The transformer primary part 44, including the primary coil, may be
entirely encapsulated by insulating material, as is the secondary
part 45. This may ensure that the coils are not exposed to touch,
which is particularly desired when the coils support peak to peak
voltages that are greater than 60 Vac. The encapsulation material
may be selected to have sufficient magnetic permeability, e.g.,
containing ferrite particles, and it may fill the entire gap 46 as
seen in FIG. 4B, where the flat outside face of the encapsulated
primary part 44 will abut the flat outside face of the encapsulated
secondary part 45 (so as to enable efficient mutual inductive
coupling between the primary coil and the secondary coil at the
switching frequency of the power converter.)
As seen in the figures, each part of the multi-part transformer may
have a flat face that becomes aligned with, and is held at a fixed
distance from, the other part of the multi-part transformer, when
the arm 4 has been coupled to the adapter 37. Note that perfect
alignment in the x, y and z-axes that are shown is not necessary
during working or operation of the arm 4. However, misalignment in
any of the axes may result in a reduction in efficiency of the
power transfer. In one embodiment, once the arm 4 is coupled to the
adapter 37, there may be an electrically insulating gap 46 of no
more than 5 mm between the primary coil and the secondary coil,
which may ensure sufficient mutual inductive coupling to deliver at
Vout(dc), 200 W at 48 V. In one embodiment, the flat outside faces
of the encapsulated primary and second parts abut each other, while
maintaining the gap 46 between the primary and secondary coils.
In the example of FIGS. 2A-2B, the primary and secondary coils are
positioned such that the mutual inductive coupling (magnetic flux)
between them is through the lateral or side faces of their
respective "housings", which are the adapter 37 and the coupling
member 40, respectively. They could however be positioned
differently. For example, the primary and secondary coils could be
positioned such that the mutual inductive coupling is through the
top face of the adapter 37 and the inner top face of the coupling
member 40, at the interface or boundary between the two housings.
In another example, the primary and secondary coils could be
positioned so that the mutual inductive coupling is through the
bottom face of the adapter 37 and the inner bottom face of the
coupling member 40.
In the example of FIGS. 2A-2B, the lateral or side faces of the two
housings of the adapter 37 and the coupling member 40 define a
vertical interface or boundary, through which the magnetic flux
lines of the mutual inductive coupling pass from one housing to the
other. This suggests that the primary and secondary coils could
have the same orientation, e.g., the length axes of both may be
vertical, as seen in FIG. 4B. But their orientation may be
different such that the interface or boundary between them need not
be vertical. For example, the two coils could be tilted in the same
direction, such that the magnetic flux lines of their mutual
inductive coupling cuts through a diagonal boundary line (rather
than a vertical boundary as seen in FIG. 4B.) In other words, the
primary and secondary coils may be oriented differently than shown
in FIGS. 2A-2C and in FIG. 4B, so that the magnetic flux lines of
their mutual inductive coupling cross an interface boundary that is
not vertical.
While certain embodiments have been described and shown in the
accompanying drawings, it is to be understood that such embodiments
are merely illustrative of and not restrictive on the broad
invention, and that the invention is not limited to the specific
constructions and arrangements shown and described, since various
other modifications may occur to those of ordinary skill in the
art. For example, while FIG. 3 depicts a resonant mode transformer
coupled power converter having a particular arrangement of a full
bridge switch circuit and a series resonant circuit in the primary
side 47, and a series resonant circuit and a full wave diode-based
rectifier in the secondary side 48, other arrangements for the
switches and resonant circuits of the power converter are possible
(e.g., a half bridge switch circuit, a parallel resonant circuit, a
series-parallel resonant circuit, and an active rectifier.) The
description is thus to be regarded as illustrative instead of
limiting.
* * * * *